The present invention generally relates to a drive arrangement for moving a glass panel of a window of a vehicle, and particularly of a motor car, which arrangement permits opening and closing the glass panel both by operation of an electric motor and by hand operation. More particularly, the present invention relates to such drive arrangement which comprises moving means for opening and closing the glass panel of the window including an input member, which input member is axially movable between two positions in which it is respectively coupled to and uncoupled from a drive shaft of the electric motor.
Drive arrangements for moving a glass panel of a window of a vehicle have been proposed, comprising moving means which permit displacement of the glass panel to a closed position, even in the case when electric drive means are turned off. These moving means comprise a hollow shaft carrying an input member, such as a gear wheel, which gear wheel can be uncoupled from a worm gear meshing with a motor-driven worm. For uncoupling the above mentioned parts, a pin of a crank handle, supporting a ball serving as coupling means, moves longitudinally in the hollow shaft against a spring operative in the direction towards coupling. This construction possesses the disadvantages that in the position of uncoupling from the motor the locking drive action of a self-locking reduction transmission attached to the same is interrupted, and the glass panel under the action of directly applied force is easy displaceable to the open position.
Drive arrangements for moving a glass panel of a window of a vehicle have been further proposed, in which additional braking means have been provided to eliminate the undesirable opening of the glass panel in the above-mentioned position of uncoupling from the motor drive. However, this construction has the essential disadvantage that the braking means affect the operating efficiency of the motor drive, which is evidently extremely undesirable.